Recently, I was tasked with displaying the GST amount for a freetext invoice. In my source code at the backend, I only had access to the CustInvoiceLine Table, while the GST amounts are stored in the TaxTrans Table. Initially, I struggled to find a direct relationship between these two tables, as multiple tables are needed to establish a relation. However, after some research, I discovered that the CustInvoiceLine already has an out-of-the-box method, displayTaxAmount(), which returns the GST amount.
Please see the screenshot below for more details.
